In a living body such as the human body, when a respiratory function or a circulatory function becomes insufficient, such as cardiac arrest (hereinafter, referred to as a cardiac-arrest state), oxygen which is supplied to a brain falls short. This shortage of oxygen may kill brain cells. In other words, it is known that it may cause so-called ischemic neuronal damage.
Hence, with respect to a living body in the cardiac-arrest state, a treatment such as artificial respiration is given for resuscitating the living body from the cardiac-arrest state. However, even if this treatment resuscitates the living body from the cardiac-arrest state, the above described ischemic neuronal damage may give a sequela to the brain.
In view of such circumstances, in recent years, hypothermic therapy is proposed as a treatment for preventing ischemic neuronal damage from being caused. In such therapy, the brain is cooled by lowering the body temperature of a living body in the cardiac-arrest state.
The sooner the hypothermic therapy is given after ischemia has broken out, the more effective it will be. In other words, as time passes, its effect will lower rapidly.
As the hypothermic therapy, there is used a method of wrapping the whole body in a blanket or the like inside of which a cooling liquid circulates, so that the temperature of a living body can be lowered. Or, for example, as disclosed in Patent Document 1, a method of directly cooling a head of a living body is used by covering the head with a mask inside of which a cooling liquid circulates.
However, in the case where the blanket or the mask is used to lower the body temperature, the body is cooled from its surface. Thus, it takes time to lower the brain temperature, and in addition, it is difficult to cool the brain adequately up to its sub-cortical tissue.
Besides, if a living body is resuscitated from the cardiac-arrest state with the whole body cooled using the blanket, the temperature of the whole body may lower, thereby inducing arrhythmia. Therefore, close attention has to be paid to timing in cooling a living body using the blanket.
In view of the above described problems, it is an object of the present invention to provide a brain cooling apparatus which is capable of cooling the brain adequately up to its sub-cortical tissue within a short period of time.    Patent Document 1: Japanese Patent Laid-Open No. 2000-60890